Conventionally, a structure is known that seals, in a state where an inserting-screw-type oil filler cap is attached to a tip end fuel filler opening of a receiving-screw-type oil filler pipe, a clearance and prevents oil leaks, so as to prevent entering of a foreign matter from the outside, by interposing and holding a ring-shape sealing member, made of a rubber or the like, between the oil filler cap and a tip end portion of the oil filer pipe (Japanese Patent Application Laid-Open Publication No. HEI8-277938).
In addition, when changing or refilling an oil contained in an oil tank, such an oil filler cap is removed from the tip end fuel filling opening of the oil filler pipe. In other cases, a state is maintained where the oil filler cap is attached to the tip end fuel filling opening of the oil filler pipe.
However, in many cases, an oil filler pipe is exposed to the outside. For example, in the field of a cutoff operation of an object by using a concrete cutter, a chain saw or the like, a large amount of dust and the like are generated due to the cutoff operation. Thus, a lot of dust and the like adhere to and are accumulated on an outer circumferential surface of an oil filler pipe provided to the concrete cutter or the like. Hence, in a normal state where an oil filler cap is attached to a fuel filler opening of the oil filler pipe, the oil filler cap and a sealing member can prevent the dust and the like from entering inside the oil filler pipe. However, when the oil filler cap is removed, and the fuel filler opening of the oil filler pipe is opened, the dust and the like, adhering to the periphery of the oil filler pipe, may enter inside the oil filler pipe from the fuel filler opening.
Additionally, in many cases, the oil filler cap removed from the fuel filler opening is temporarily placed on the outside ground or the like where the dust and the like are scattered. Then, after an oil is changed or filled, the oil filler cap is attached to the fuel filler opening again. Hence, there is a problem in that the dust and the like adhering to the oil filler cap enter inside the oil filler pipe.
Therefore, an object of the present invention is to provide a cap of a refilling pipe and a refilling pipe that can prevent dust and the like from adhering in the vicinity of the fuel filler opening of the oil filler pipe and the periphery of the oil filler pipe, and can prevent the dust and the like from entering inside the oil filler pipe, when closing the fuel filler opening after the oil is changed or refilled.